Exhauster for alpha dry pipe valve system



Oct. 17, 1933. E BENS N 1,930,580

EXHAUSTER FOR A DRY PIPE VALVE SYSTEM Filed Oct. 11, 1929 2 Sheets-Sheet 1 Ell.

Get. 17, 1933. E, so 1939,58

EXHAUSTER FOR A DRY PIPE VALVE SYSTEM Filed Oct. 11, 1929 2 Sheets-Sheet 2 Patented Got. 17, 1933 v EXHAUSTER FOR A DRY PIPE VALVE SYSTEM Emil Benson, Worcester, Mass, assignor to Rock wood Sprinkler Company of Massachusetts, Worcester, Mass a corporation of Massachusctts Application October'll, 1929. Serial No. 395,061

7 Claims. (Cl. 169-47) This invention relates to an improvement in exhausters which are devices for causing the valve of a dry-pipe sprinkler system to open more quickly after a sprinkler head has been opened by heat, by exhausting the compressed air through a large valve outlet.

The principal object of the improvement is to make the exhauster both smaller in size and more sensitive to quick opening, on the initial "motive air impulse, produced when the sprinkler head opens. The advantage of reducing its size is that the exhauster becomes cheaper to make and occupies less room when connected. to the sprinkler system. To this end the improvement provides means whereby the diaphragm, which is operated when the air pressure on the system side decreases, can be made of minimum diameter, thus materially reducing the size of the casting in which the operating parts for opening the air port are located. The improvement also provides a construction inwhich a single casting can be used both for the chamber which retains the original pressure of the sprinkler system after a sprinkler head has opened and the chamber containing the eidiaust port and valve.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings in which Fig. 1 is a sectional view of a quick exhaust system constructed in accordance with this invention, and

Fig. 2 is a sectional view of the same on the line 22 of Fig. 1.

This invention is shown as applied to a sprinkler system comprising a riser 10 and a pipe 11 delivering to the system. Between these is a T 12. The dry-pipe valve 9 of the system is located at the end of the pipe 19, or elsewhere, as may be convenient. It will be understood that this invention is applicable to numerous types of valves. For that reason no particular one is shown.

The tting 12 which communicates with the pipes 10 and 11 is connected with an exhauster through a gate valve 13 and is provided with the usual screen 8. This gate valve is normally open so the air in the sprinkler system enters the exhauster and is held at full pressure in a chamber 14 in a casing 7 and also communicates through an open passage with an upper chamber 15 located in a cover 6 on the casing. It also communicates through a restricted opening in a plate 16 with a second chamber 17 in the casing 7.

In the chamber 14 is a valve 18 normally closed against its seat, for allowing the air to escape rapidly through a pipe 19 to the outer air when this valve is opened. This'valve 18 is secured on a stem 20 which passes through a partition 21 between the chambers 14 and 17. The opening through this wall is closed by a sylphon 22 which is of the usual type except that, instead of having a solid end, it is perforated to allow the stem 20 to pass through it and has a head 23 screwing down a screw thread on the-valve stem 20 to tighten up a packing 24 against an enlargement 25 fixed on the stem.

The valve stem passes through, and is fixed to, a pressure-actuated device for operating the valve. This device consists of a plate 27 secured 70 to the center of a diaphragm 28. The valve stem extends at the top into an upper; sylphon 29. Diaphragms are now loyed for the same purpose as this one, but this is reduced in size to the minimum, as will appear. For protection the sylphon 29 is locate. in a cap 30 which is con nected with the atmospheric air through ports 31. The interior of the sylphon communicates with the chamber 15.

They chamber 1'? is provided with an outlet valve pressed to its seat by a spring and guided by a valve rod 36. Whe raised, it discharges into a chamber 37 and into the outer air through the air vent 38. The intermediate chamber 5 of the dry-pipe valve, which is closed off from the Water before operation but is under pressure when the dry-pipe valve opens, is connected to the interior of the sylphon throngthe pipe 40. When the dry-pipe valve opens, water will press against the top 42 of the sylphcn and push up the stem of the valve 35, thereby allowing the air in the chamber 17 to escape and permit the valve 18 to return to its seat.

The operation of the rest of the device is as follows: As long as the sprinkler system is under the necessary air pressure this pressure acts on the top of the valve 18 to keep it closed. The diaphragm 28 is balanced because the pressure on both sides is the This pressure also acts on the inside of the sylphcn 29 to resist the 100 pressure on the valve 13 but the area is smaller than that valve so the valve 18 is kept closed in spite of this pressure on the sylphon.

The sylphon 22 does not affect the situation because it simply acts as a stufiing box or the 105 like to come and go with the valve stem and to prevent leakage from the chamber i l into the chamber 1?. Normally the air pressure is equalized on both sides of it.

Now when one of the sprinkler heads opens the 11 pressure in the chambers 14 and 15 is suddenly reduced a few pounds per square inch. There is still pressure on the valve 18 but not quite the maximum. As, however, the chamber 17 cannot vent through the valve 35 at this time and is connected to the chamber 14 only by a restricted passage, the pressure therein remains for the time being at the maximum. As the pressure in the chamberlfa is reduced the unbalanced upward pull on the valve stem 20 increases and the valve 18 will rise. On account of'the slight original difference betvven the total pressure on the valve 18 downwardly and the total effective pressure upwardly in the sylphon 29 and of the further fact that as upward motion of the valve 18 takes place the downward pressure is quickly reli ved, this motion is very quick, much quickerthan has been the case heretofore, when no sylphons were used. Therefore the air is allowed to escape from the system very suddenly through the wide open valve 18. Now when the water comes through t -e dry pipe valve it first opens the air valve 35, allowing the pressure in the chamber to descend to that of the atmosphere, and it also enters the chamber 15 and forces the diaphragm down again, closing the valve 18. The 7 water pressure obviously will keep this valve closed as long as the water remains the system. The water may be drained and the system re-set after the fire is out.

It will be seen that, on account of the increasing assistance which the sylphon 29 gives to the opening of the valve 18, after the lifting action once starts, that action takes place very quickly; 3 and because 'sylphon and valve nearly balance each other, the diaphragm 28 can be made of smaller diameter than has been possible without using the sylphon. This reduces the size of the whole device. Furthermore, on account of this design, which employs no valve or lever in the chamber 15, the cover plate 6 may be made nearly fiat and hence of minimum weight and cost, and the casting 7 or the like containing the chambers 17 and 14 can be made all in one piece, thus reducing the expense and complication of this castin Although I have illustrated and described only one form of the invention I am aware of the fact that modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited in this respect but what I do claim is:

1. In an exhaust-er for a dry pipe system, the combination with two chambers connected with each other by a restricted orifice so that the second chamber will gradually attain the pressure of the system and retain it after air is allowed to escape from the first chamber, the first chamher being connected with the system to receive the air pressure and having an ou let for the compressed air, of a valve for normally closing said outlet, said valve being held closed by the pressure in the system, a pressure actuated device, having the pressure of one chamber on one side and the other chamber on the other, connected with said valve to open it when the pressure in th system is lowered and the pressure in the second chamber is maintained, and means exposed on the inside to the'pressure in the firsu chamber and to the atmosphere on the outer side, connected with the valve for resisting the tendency of the pressure in the systemto keep the valve closed but not capable or entirely overcoming it, whereby the said means will assist in opening the valveand result in a rapid opening thereof.

2. In an exhauster for a dry pipe system, the combination with a casing having two chambers therein separated from each other and having an outlet for the compressed air of the system, of a valve" for normally closing said outlet located in such position that the pressure or" the air in the system, holds it closed, one of the chambers being connected with the system to receive the air pressure, and having said valve therein, the other chamber being connected with the first chamber by a restricted connection, so that it will attain he pressure of the system and retain it after air is allowed to escape, a pressure actuated device having the pressure of one chamber on one side and that of the other chamber 011 the other side, connected with said valve to open it when the pressure in the system is lowered and the pressure in the second chamber is maintained, and a sylphon connected with the valve for resisting the tendency of the pressure in the system to keep the valve closed but not capable of entirely overcoming it, whereby said sylphon will assist in opening the valve and result in a rapid opening thereof.

3. In an exhauster for a dry pipe system, the combination of two chambers separated from each other, one connected freely and directly with the system and the other connected through a restricted orifice with the first chamber, whereby the pressure of the system will gradually build up in the second chamber and when the pressure in the system is suddenly reduced that in the second chamber will be maintained, a dia phragm having the pressure of onechamber on one side and that of the other on the other side, a valve stem secured to said diaphragm and movable therewith, a valve on said stem, an outlet from the system controlled by said valve, the valve being located on the same side of the diaphragm as the second chamber, whereby when the pressure is reduced in the system the diaphragm will be moved to pull the valve away from its seat, and a sylphon having an area open to the atmosphere on the outside, connected on the inside to said valve stem and open to the pressure of the air in the system on the inside, said area being less than that of the valve acted on by the pressure of the system, whereby said sylphon will resist the closing of said valve but not prevent it, thus assisting in the rapidity of opening the valve.

4. In an exhauster for a dry pipe system, the combination with a casing having a partition therein dividing it into two chambers, said two chambers being connected through a restricted opening, one chamber communicating with the dry pipe system andhaving an outlet valve seat through which the air can be exhausted, a diaphragm between the two chambers, a valve stem secured to said diaphragm and projecting beyond it in both directions, a sylphon having an area open internally to the air pressure in the first chamber and open to the atmosphere on its exterior and secured to said valve stem on one side of the diaphragm, and a valve for said valve seat connected with said valve stem on the other side of the diaphragm and having an area greater than the first mentioned area in position to be acted on by the pressure of the system.

5. In an exhauster for a dry pipe system, the combination with a casing having a partition across the same dividing it into two chambers, said two chambers being connected through a nally to the air pressure in the cover and open to the atmosphere on its exterior and secured to the end of said valve stem which extends away from the second chamber, a valve for said valve seat connected with the other end of said valve stem and having an area greater than the first mentioned area in position to be acted on by the pressure of the system, said valve stem passing through said partition, and a sylphon connected with the valve stem inside the second chamber and its free end connected With said partition to prevent the passage of air through the partition around the valve stem.

6. In an exhauster for a dry pipe system, the combination of two chambers separated from each other, one connected freely with the system and the other connected through a restricted orifice with the first chamber, a diaphragm having the pressure or" one chamber on one side and that of the other on the other side, a valve stem secured to said diaphragm and movable therewith, a valve on said stem, an outlet from the system controlled by said valve, a sylphon under the pressure of the air in the system for partially counteracting the efiect of the pressure of the air in the system on said valve to keep it closed, a spring pressed, normally closed, valve forv preventing the escape of air from the second chamber, a discharge opening normally closed by the last named valve, a second sylphon connected with the last named valve to open it upon the introduction of pressure inside the last named sylphon, and a fiood valve having a groove, said sylphon being connected with the groove in the flood valve of the water system to fill with water under pressure when the flood valve opens, whereby the second chamber will thereby be exhausted rapidly.

'7. In an exhauster for a'dry pipe system, the combination with a casing having a partition dividing it into two chambers, said two chambers being connected through a restricted opening, one chamber communicating with the dry pipe system and having an outlet valve seat, a cover for the casing connected with the first named chamber to receive the pressure thereof, a diaphragm between the cover and the second chamber of the casing, a valve stem secured to said diaphragm and projecting beyond itin both directions, a sylphon open internally to the air pressure in the cover and secured to the end of said valve stem which extends away from the second chamber, a valve for said valve seat connected with the other end of said valve stem, said valve stem passing through said partition, a sylphon connected with the valve stem inside the second chamber and its free end connected with said partition to prevent the passage of air through the partition around the valve stem, a discharge opening for allowing the escape of air from the 1 second chamber, a spring-pressed, normally closed valve for said discharge opening, a sylphon connected with said valve to open it upon the introduction of pressure inside it, the last named sylphon being connected to fill with water under pressure, whereby the second chamber will thereby be exhausted rapidly.

EMIL BENSON. 

